1. Field of the Invention
The present invention relates to a plug, and more particularly to a safety plug.
2. Description of the Prior Art
Typical plugs include at least two prongs extended outward from the body for plugging into a socket and the like, however, part of the prongs are exposed if the plugs are not fully plugged into place. This is dangerous if children inadvertently electrically couple the prongs by metal materials or if children touch the prongs simultaneously.
In order to solve the problems, people develop several kinds of safety plugs for protecting the prongs of the plug. One of the safety plugs is disclosed in U.S. Pat. No. 3,754,205 to Lenkey, filed on May 19, 1971, in Lenkey, the prongs are not stably retained in place and apt to become loose and will be easily disengaged from the plug; in addition, a tubular integral spring socket is formed in the center portion of the plug, however, in view of manufacturing process, a shaft or a rod should be engaged in the spring socket after the plug is molded, the spring socket will hold the rod solidly such that the disengagement of the plug from the rod is very difficult and has become a serious problem. Furthermore, when using the safety plug, the detents formed integral with the cover are exposed in the area where the fingers of the user hold the plug, such that the movement of the detents and thus of the cover will be interfered or be interrupted.
Another type of safety plug is disclosed in U.S. Pat. No. 5,030,119 to Lowe filed Sep. 27, 1989, in Lowe, the forward housing member and the protective cover are both made of resilient materials and contacted with each other, the protective cover will be held tight within the housing member when the user grips the housing member of the plug, such that the movement of the protective cover will also be interfered or be interrupted. In addition, the prongs have only a small part held in the respective blade holding arms such that the blade holding arms can not stably and solidly hold the prongs in place. Furthermore, the conductors embedded in the plug may have penetrating strands or burr which may be extended into the hole during molding processes, such that the penetrating strands or burr may contact the spring received in the hole, and such that the prongs will be electrically contacted with each other by the spring and such that shortage may happen.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional safety plugs.